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881.
Eri Tanida Kan Usuda Koichi Kono Atsuko Kawano Hiroshi Tsuji Masafumi Imanishi Shinichi Suzuki Keiko Ohnishi Kimiyo Yamamoto 《Biological trace element research》2009,130(3):273-282
Some of the rare earth elements such as Sc are believed to be non-toxic and, at present, are widely utilized for the replacement
of toxic heavy metals in technological applications, but they are not entirely free of toxicity, with hidden potential health
risks. In this animal experiment, we report the urinary scandium (Sc) excretion rate and nephrotoxiciy in male Wistar rats.
For this purpose, the rats were given a single dose of a solution of scandium chloride by intraperitoneal injection. The Sc
excretion (U-Sc) was determined in 24-h urine samples by inductively coupled plasma–argon emission spectrometry along with
the Sc nephrotoxicity, urine volume (UV), creatinine (Crt), β-2-microglobulin (β2-MG) and N-acetyl-β-d-glucosaminidase (NAG). A dose-dependent Sc excretion of 0.0063% (r = 0.97) via 24-h urine was confirmed. The administration of Sc induced a significant decrease of UV and Crt and a significant
increase of NAG and β2-MG. These results suggest that U-Sc can be a useful tool for monitoring Sc exposure. The formation
of Sc colloidal conjugates that deposit in glomeruli may be the cause of a reduction of the glomerular filtration rate. We
propose that the analytical method and results described in this study will be of great importance for future toxicological
studies on Sc exposure. 相似文献
882.
Postmortem Changes in Catecholamines, Indoleamines, and Their Metabolites in Rat Brain Regions: Prevention with 10-kW Microwave Irradiation 总被引:5,自引:4,他引:1
Postmortem changes in catecholamines, indoleamines, and their metabolites in rat brain regions following decapitation were determined by LCEC. In the three regions studied neurotransmitter levels declined after decapitation, whereas the metabolite levels increased. Microwave irradiation at 10 kW rapidly inactivated brain enzymes and thus prevented the postmortem changes. 相似文献
883.
Jan Holgersson Annika E. Bäcker Michael E. Breimer Mikael L. Gustavsson Per-Åke Jovall Hasse Karlsson Weston Pimlott Bo E. Samuelsson 《生物化学与生物物理学报:疾病的分子基础》1992,1180(1):33-43
Blood group A glycolipid antigens have been found based upon at least four different core saccharides (types 1 to 4). The biological significance of this structural polymorphism is not known, although the successful outcome of transplantations of blood group A2 kidneys to blood group O individuals have been partly explained by the low expression of A type-3 and -4 chain glycolipid antigens in A2 kidneys. If graft rejection due to ABO incompatibility is, in any way, correlated to the expression of type-3 and -4 chain blood group glycolipids, it is of interest to identify possible blood group B structures based on these core saccharides. In a non-acid glycosphingolipid fraction isolated from human blood group B kidneys, mass spectrometry, high-temperature gas chromatography-mass spectrometry and probing of thin-layer chromatograms with Galα1–4Gal-specific Escherichia coli and monoclonal anti-B antibodies provided evidence for minute amounts of Gaα1–3(Fucα1–2)Galβ-HexNac-Galα1–4Galβ-Hex-Ceramide structure consistent with a B type-4 chain heptaglycosylceramide. In contrast, blood group A kidneys have the corresponding A type-4 chain heptaglycosylceramide as the predominant glood group A glycolipid. No, or very low activity of the blood group B gene enzyme on the type-4 chain blood group H hexaglycosylceramide precursor was found by biosynthetic experiments in vitro, which migh explain the low expression of type-4 chain blood group heptaglycosylceramides in human blood group B kidneys. 相似文献
884.
885.
Abd El-Moneim M.R. Afify Gamal S. El Baroty Farouk K. El Baz Hanaa H. Abd El Baky Soha A. Murad 《Journal of Genetic Engineering and Biotechnology》2018,16(2):399-408
Purpose
To obtain protein hydrolysates from fresh water green algae Scenedesmus obliquus by three different enzymes and evaluate its antioxidant and antiviral activity.Methods
Enzymatic hydrolysates of green algae Scenedesmus obliquus protein were prepared by treatment with: 1.2% solution of pepsin, trypsin or papainResults
S. obliquus cells and protein extracts were rich in Arg, Lys, Asp, Ala, and His. Protein hydrolyzed by papain (Sd1pa) and protein hydrolyzed by trypsin (Sd2Try) induced highest antioxidant activity based onConclusion
S. obliquus protein hydrolysates have a potential as antioxidative neutraceutical ingredients and a potential therapeutic agent against CVB3. 相似文献886.
887.
Functional expression of rat renal Na/Pi-cotransport (NaPi-2) in Sf9 cells by the baculovirus system
The recently cloned Na/P
i
-cotransport system NaPi-2 is an apical membrane protein of rat proximal tubular cells and is involved in proximal phosphate reabsorption. To make the protein available for further functional/structural studies, this transport system has been expressed in Sf9 insect cells using a recombinant baculovirus. Sf9 cells infected with NaPi-2 (or 6His tagged NaPi-2) expressed functional Na/P
i
-cotransport up to 20- to 50-fold over noninfected Sf9 cells. Transport of phosphate in infected cells was highly dependent on sodium, exhibited a K
m
for P
i
of 0.114 mm and an apparent K
m
for Na of 63 mm (Hill coefficient of approximately 3) and was stimulated by high external pH. Infected cells expressed a polypeptide of 65 kDa representing a nonglycosylated form of the 85 kDa mature NaPi-2 transporter as present in proximal tubular brush-border membranes. By confocal microscopy expression of NaPi-2 protein was observed in the plasma membrane, yet submembranous accumulation of NaPi-2 protein could not be excluded. This demonstrates that the rat proximal tubular Na/P
i
-cotransport system NaPi-2 can be successfully expressed in Sf9 cells with characteristics similar to that in isolated brush-border membranes. The 6His tagging will permit isolation of the NaPi-2 cotransporter in amounts sufficient for structural/functional studies.We would like to thank W. Scherle and M. Lötscher (Institute of Anatomy) for their generous help using the confocal microscope and Ch. Gasser for the art work. Financial support by the Swiss National Fonds [Grant No. 32-30785.91 (to H.M.) and 32-28664.90 (to J.B.)] and by Stiftung für wissenschaftliche Forschung an der Universitát Zürich is greatly acknowledged. 相似文献
888.
Leonid Yu. Sklyarov Irina N. Sbitneva Nadezhda A. Kopina 《Letters in Peptide Science》1995,2(3-4):247-252
Summary Heterocycles (pyridines and pyrroles) obtained from amino acid derivatives and unsaturated compounds can be considered as peptidomimetics. These compounds contain amino acid radicals and modified, nonhydrolysable peptide bonds (micromimetics). The polyfunctionality of pyridoxine (one of the most available pyridines, derived from N-formyl -alanine amide/ester) offers the possibility for use in the synthesis of multiple peptides (MPs). In view of the fact that MPs have certain structures and molecular weights and also owing to the proximity of several peptide chains, they may be considered as models of proteins and even of cell surfaces (macromimetics). Dendritic compounds — multiple spherical peptides — most closely imitate globular proteins. The potential for macromimetics to model the various functions of biopolymers is investigated here. 相似文献
889.
A putative FAD-binding domain in a distinct group of oxidases including a protein involved in plant development. 总被引:5,自引:0,他引:5 下载免费PDF全文
A. R. Mushegian E. V. Koonin 《Protein science : a publication of the Protein Society》1995,4(6):1243-1244
Using methods for database screening with individual protein sequences and alignment blocks, a conserved domain is delineated in a group of proteins including several FAD-dependent oxidases. Two motifs within this domain resemble phosphate-binding loops and may be directly involved in FAD binding. These motifs can be readily distinguished from previously described nucleotide-binding sites using a method for database screening with position-dependent weight matrices derived from alignment blocks. Unexpectedly, this group of known and predicted FAD-dependent oxidases includes the product of the DIMINUTO gene, which is involved in Arabidopsis development, and its homologues from man and Mycobacterium leprae. 相似文献
890.
Marianne Pons Olivier Forpom s St phane Espagnet Jean Cambar 《Chronobiology international》1996,13(5):349-358
Circadian changes in renal hemodynamics and urinary glycosaminogly-can (GAG) excretion were studied in normal Sprague-Dawley rats to further investigate rhythms in kidney function. Urinary water, protein, and GAG excretion, as well as glomerular filtration rate (GFR) and renal plasma flow (RPF), were determined every 4h over the 24h cycle in an attempt to characterize any temporal changes. Urinary flow rate and proteinuria peaked during the dark activity period of the animals, consistently at the same hour, whereas the lowest values were detected during the resting phase. GAG are mucopolysaccharides entering the constitution of the glomerular basement membrane (GBM), which is the key component in the process of glomerular filtration. Similarly, the urinary excretion rate of GAG showed a circadian rhythmicity in phase with urinary water and protein excretion, with markedly increased values observed during the nocturnal phase of the animals. Moreover, GFR and RPF were demonstrated to exhibit large circadian variations in phase with renal excretory rhythmicity, showing nighttime values significantly greater compared to daytime ones. Strong correlations were found between GFR and RPF rhythms, as well as between GAG and GFR, and GAG and RPF rhythms, although the latter were not statistically significant. This pattern suggests that the circadian rhythmicity in urinary excretion rate of GAG in physiological conditions could presumably be secondary to the temporal changes in renal hemodynamics. In this respect, knowledge of renal chronobiology helpfully contributes to increase our understanding of renal physiology. 相似文献